Switching means



July 18, 1939. E, Q LACEY 2,166,498

SWITCHING MEANS Filqd Nov. 10, 1937 6 v i 73 l' CF ce 1/ 66 /Nvefv of 70 F J.

Patented July 18, 1939 SWITCHING MEANS' Ernest George Lacey, East Kew, Victoria, Australia Application November 10, 1937, Serial No. 173,902 In Australia April 7, 1937 18 Claims.

This invention relates to improvements in and connected with electric circuits ofinternal combustion engines and/or of associated apparatus and refers especially, but is not limited, to the electric circuits of motor vehicles.

It occasionally happens, that, through inadvertence, the ignition switch of a motor vehicle is left closed for 'lengthy periods when the engine is not running and as a result the storage battery l0 is sometimes discharged through the primary winding of the aforesaid ignition coil, so that it is subsequently unable to supply sufficient current to actuate the starting motor of the vehicle. The battery may also run down if any of the lighting circuits are inadvertently left closed.

Now, the chief object of the present invention is to provide improvements in protective switching means of a motor vehicle adapted to prevent the battery circuit from being inadvertently left closed when the vehicle is not in use.

One broad feature of the invention resides in providing the battery circuit auxiliary switch means arranged to temporarily close the said circuit when the engine is being started, characterised in that the said switch means is so constructed as to be closed by direct or indirect manual operation and to maintain the battery circuit closed for a predetermined minimum period.

Automatic switch means are also provided to maintain the battery circuitclosed when the engine starts and to open the said circuit when said engine stops or when further operation thereof is undesirable, said automatic switch means being preferably controlled by means responsive to the pressure of the lubricating oil, though it may be actuated by any other means responsive to the operation of the engine.

rFhe aforesaid auxiliary switch means and the automatic switch means may be arranged in parallel between the battery and the ignition and/or other devices to be energised thereby, or alternatively a single switch may be provided, said switch being operable independently by said auxiliary switch means and by said automatic means. By employing switch means which maintain the battery circuit closed for a predetermined minimum pericda suicient time lag is provided to enable the automatic switch means to become effective before the auxiliary switch means are rendered ineffective.

Another feature of the invention resides in the provision of bimetallic strip means arranged to eiect a positive opening movement of the aforesaid automatic switch means.

'I'he said auxiliary switching means preferably embodies a resistance wire through which current is caused to pass when the engine is about to be started whereby said wire will expand owing to the increase in temperature, such expansion 6 being utilised to eifect the closing of the aforesaid switch. When the resistance wire is de-energised, the rate at which it cools and contracts determines the period of the time lag which will occur in the opening movement of the switching means. 10 Preferably the resistance wire is arranged in parallel with .the starting motor so as to be energised when the usual starting switch is actuated.

In the drawing:

Figure 1 is a view in elevation of a switching 15 device in accordance with the invention and is shown as connected to the relevant electrical circuits of a motor vehicle.

Figure 2 is a view in sectional plan taken on the line 2--2 of Figure 1. 20

Figure 3 is a view in vertical section taken on the line 3--3 of-Figure 1.

Figures 4, 5 and 6 are views similar to Figure 1 and show different stages in the operation of the switching device.

Figure 7 is a detail view of portion of the switching device shown in Figure 1 and is drawn to a larger scale.

Figure 8 is a view in vertical section of changeover means incorporated in the switching device 30 and is drawn to a larger scale, and

Figures 9, 10 and 11 are views similar to Figure 1 and illustrate modied forms of the switching device.

In the drawing the invention is shown as 35 adapted to the one wire system or wiring in which one terminal of the battery is' earthed to the chassis of the vehicle but it will be understood that the invention is equally applicable to the two wire system.

Referring now to Figures l, 2 and 3 of the drawing the reference numeral I0 designates an elongated metal casing which is mounted in any convenient position on a motor vehicle and connected to earth as diagrammatically indicated at 45 I I.v This casing is open at one side which is fitted with a detachable cover plate I 2.

A flexible ribbon I3 of nichrome or the like hereinafter referred to as the thermal wire is arranged substantially longitudinally within the 50 casing and adjacent the top thereof, this wire being supported at one end on a member forming part of a terminal I4 which projects from the adjacent end of the casing.

The opposite end of the thermal wire I3 is 55 Wrapped around a screw I5 which is disposed laterally within the casing and which permits of a tension being imparted to the said wire. The screw I5 also serves to connect the adjacent end of the thermal wire to earth.

The terminal I4 is connected by a conductor to the usual starting switch I6 located between the battery I1 and the starting motor I8 with the result that the thermal wire is energised and deenergised in unison therewith.

A resilient contact arm I9 is arranged horizontally below the thermal wire and has its fixed end received in a slot provided in a block 20 of the insulating material suitably secured to the casing. An external terminal 2| is electrically connected to this xed end of the contact arm I9.

The free end of the` arm I9 is bent upwardly and carries a bush 22 of insulating material through which the central position of the thermal wire extends. The arm I9 has a downward bias and consequently a downward pressure is exerted thereby on the thermal wire.

An insulated stop member 23 is fitted to the top of the casing somewhat above the top of the upwardly bent free end of the contact arm I9.

The second resilient contact arm 24 is arranged substantially horizontally within the casing below the arm I9 and its fixed end is similarly mounted in the block 20 and is connected to an externalv is disposed just outof engagement with a simi-v lar contact member 21 fitted to the underside of the upper contact arm I9.`

The-lowerarm 24 is doubled back upon itself for a short distance and is then bent forwardly over the adjacent end of a strip 28 of insulating material.

It will be noted that the free end of the metal strip forms a shoulder 29 and the -depth of this shoulder slightly exceeds the width of the gap between the contact members 26 and 21.

A bimetallic strip 30 is located substantially vertically within a' central downward extension of the casing IIJ and the lower end of this bimetallic strip is clamped thereto while the upper end is free to move laterally.

When the bimetallic strip is not heated it tends to assume a vertical position, but when the device is in the condition shown in Figure 1 this is prevented by a conductor cap 3I on the upper end of the bimetallic strip abutting against the aforesaid shoulder 29 on the lower surface Vof the free end of the Contact arm 24. (See also Figure 7.)

'I'he conductor-cap 3I-is insulated from the bimetallic strip but is connected by a conductor 32 (shown diagrammatically in Figure 3) to the adjacent end of a resistance winding 33 which surrounds the central portion of the bimetallic strip, the opposite end of this winding being earthed, by a conductor 34, to the'adjacent portion of said bimetallic strip.

The contact arm 24 also has a downward` bias whereby it normally rests on the upper end of a stop member secured vto the casing. This stop member-is formed with an axial bore which accommodates a plunger 3610i insulating material. (See Figure 8.) AA compression spring 31 serves to maintain the lower end o`f the plunger in conmay be raised as indicated in Figure 8 whereby.

` by a switch 60.1

the contact arm 24 is moved upwardly to cause the contact 26 to engage contact 21.

A diaphragm chamber 40 is secured to a lower portion lof the casing and is provided in the well-known manner with a resilient diaphragm having a downward bias. The lower compartment of the diaphragm is connected by a pipe 4I to the pressure lubricating system of the engine of the vehicle, while a vertical plunger 42 arranged with its lower end in contact with the top of the diaphragm, has its upper end projecting into the casing and tted with a cap 43 of insulating material.

The terminal 2l for the contact arm I9 is connected to the battery of a conductor 44 while a conductor 45 connected to the terminal 25 serves for the supply of current to the ignition and other suitable electrical equipment of the vehicle.

The usual ignition switch is diagrammatically indicated at 46 in series with the primary winding 41 of the ignition coil and the mechanical interrupting device 493.

'Ihe headlamps 49 are arranged to be placed in circuit with the conductor 45 by means of the usual switch 50 and in thearrang'ement shown in Figure 1 this switch is mechanically coupled to a switch 5I arranged in circuit with parking lamps 52. The lupper contact of the switch 5l is connected by a conductor 53 to an insulated contact 54 arranged within the casing and normally engaged by a resilient contact strip 55 secured to the free end of the contact arm I9.

The switch 56 in circuit with the conductor 45 may be arranged to control an electric horn (not shown) whilst the switch 51 may be arranged in circuit with a wireless receiving set (not shown). It is to be understood however that any desired electrical equipment may be connected in circuit with the conductor 45 through a suitable switch.

The electric generator (not shown) is connected` in the usual way to the battery through the usual automatic cut out switch diagrammatically indicated at 58.

In some cases it may be desired to energise the parking lamps vand/or certain other electrical equipment direct from the battery in the usual way andthe reference numeral 59 designates by way of example one such lamp which is controlled Now when the engine of the vehicle is not operating the device is in the condition shown in Figure 1, the conductor 45 being disconnected from the battery I1 at .the contacts 26-21. Consequently no current passes through the ignition coil 41 if the switch 46 has been inadvertently left closed and likewise the closure of switches 50, 5 6 and 51 would be without eiect upon the devices in circuit therewith. It is to be I switch 50 causes the parking lamps 52 to be energised through a 'circuit extending from the battery by way of conductor 44, terminal ZI,

lspring contact arm I9, c ontact strip 55, insulated contact 54, conductor 53, switch 5I and parking lamps 52 to earth'.

The engine of the vehiclemay be startedup in the usualway by .closing the ignition switch 46 and depressing the starterv switch I6. The ,actuation of the latter switch simultaneously energizes the starting motor' I8 and -the thermal wire I3 which are connected in parallel. As the thermal wire is formed of nichrome or the like requisite value.

it is heated by the passage of current to such an extent that the resultant expansion thereof enables the contact arm I9 to move downwardly until the contact 21 thereon engages the contact 26 thereby closing the ignition circuit and also the circuit of the headlamps 49, if it be assumed that switch 5D was previously closed. (See Figure 4.)

The engine therefore starts up in the usual way and the lubricating oil is circulated. by the usual pump so that the pressure thereof is increased. When the oil pressure reaches a safe working value the resistance of the resilient diaphragm within the diaphragm chamber 40 is overcome and the diaphragm is displaced upwardly thereby raising the plunger 42 so that the cap 43 on the upper end thereof engages the underside vof the contact arm 24. The Contact arm 24 is thus forced upwardly together with the contact arm i9 until further movement is prevented by the upwardly turned free end of the contact arrn i9 moving into engagement with the insulated stop member 23. (See Figure 5.) Consequently the contacts 26 and 21 which are initially closed as a result of the expansion of the thermal wire are maintained closed by the pressure of the lubricating oil when the engine is running. It will be evident that in lieu of arranging the diaphragm plunger to directly actuate the contact arm 24, said plunger may be utilised to close a switch in thel circuit of an electromagnet arranged to attract the said contact arm.

It is to be noted also that the upward displacement of the contact arm 24 enables the bimetallic strip 30 to assume the vertical position and that the contact spring 55 is disengaged from the insulated contact 54 -thereby breaking the circuit of the parking lamps 52. At this time, however, the head lamp circuit is closed by means of contacts 26-21 and the switch 5G.

Now it is important to note that ir for any reason the oil pressure does not immediately build up to a safe value when the engine is started, the contacts 26-21 do not reopen as soon as the starter switch I5 is released because a time delay takes place while the thermal wire is cooling and contracting. This time delay in the tendency of the contacts 26--21 to reopen 'con--V stitutes an important feature oi the invention because it ensures that the contacts will remain closed for a suillcient time after the engine has started to enable the oil pressure to rise to the The duration of the time delay may be varied by varying the resistance of the thermal wire or by controlling the rate of dissipation of heat therefrom.

Assume now that the oil pressure falls below the safe operating value either as a result of the ignition switch 46 being opened to stop the engine or the engine being stalled or of a 'defect occurring in lthe lubricating system. The reduction in the oil pressure enables the resilient diaphragm in the diaphragm chamber 40 to return to its lower position thus causing the contact arms 24 and i 9 to move downwards in unison until the under surface of the free end of the strip forming the arm 24 engages the electrically conducting cap 3! on the top of the bimetallic strip 30. (See Figure 6.) this downward movement of the arm 24 is insuiiicient to enable the contact 26 to be disengaged from the contact 21 and-thus the ignition and headlamp circuits remain closed as shown in the figure.

It will be noted that 'Ihe resistance winding of the bimetallic strip however is now energised through a circuit extending from the battery through contact arm I9, contacts 2126,- contact arm Zl, conductor cap 3| on the bimetallic strip, conductor 32 and winding 33 to earth. The increase in temperature of the bimetallic strip consequent upon the energisation o! the Winding 33 causes the upper end thereof to move towards the left of Figure i so that after the lapse oi a predetermined time, the conductor cap 3l passes over the shoulder E@ thus enabling the contact arm 2t to further descend through a distance equivalent to the depth of the said shoulder, at the same time causing the contact. 26 to be separated from the con tact 2l. The winding 33 oi' the bimetallic strip and the circuits supplied with current through the conductor are thus de-energised so that the device is restored to the condition shown in Figure i'oi the drawing.

One advantage oi the bimetallic strip iid-is that it provides a time lag which serves to maintain the conductor t5 energised for a predetermined period if the engine should stall, while a further advantage is that it minimises arcing at the contacts Pt-21 by ensuring a rapid opening movement thereci'.

In some cases it may be advantageous for the switches 50 and 5i for the headlamps and parising lamps respectively to be actuated independently oi each `other while as previously stated and as shown at 5S in Figure 1 the parking lamps may connected to the battery independently of the protective switching apparatus arranged wlthin the casing lo.

By turning the arm 39 and 'raising the insulated plunger 38 in the stop member 35 as shown in Figure 8 the contact 26 on the lower contact arm 24 may be constantly held in engagement with the contact 21 on the contact `arm I9 so that the electrical equipment in circuit with the conductor 45 may be energized in the orthodox manner, i. e. irrespective of whether the engine is running. A signal device may be arranged for operation by the arm 35i so as tol be energised when theplunger 36 is raised theroc by warning the driver that the protective switch is not in operation.

Figure 9 shows a modification in which a third spring contact arm 64 is located within the casing i0 below the arm 24, the free end of the arm $4. being normally disposed out of contact with the arm 24. The arm B4 normally rests upon the top of the earthed stop member 3d and the plunger 42 or the diaphragm chamber 4t is ar' ranged to engage the said arm tl.

A terminal 65 connected to the outer end oi the arm 54 is connected to the automatic cut out switch 58 oi' the usual electric generator which is not shown. Thus in this modification the cut out switch instead of being. connected direct to the battery 'in the usual way as shown in'Flgure i is connected to the contact arm del.

The upper contact armA I 9 is connected to the battery I1, as in Figure 1 and likewise the contact arm 24 is connected to the conductor t5 leading to theignition and other switches shown in Figure l.

It will be evident that this apparatus operates substantially in the same manner as the construction previously described except that the automatic cut out switchof the generator is not connected in circuit with the battery until the oil pressure rises to a value suiiicient to displace the diaphragm contained in the diaphragm chamber 48.

In the event of the oil pressure failing, .the descent of the plunger 42 enables the contact larm 64 to descend out of contact with the arm 24, but damage to the generator is prevented by said arm 64 moving into engagement with the learthed stop member 35. Subsequently after a lapse of time the duration of which is determined by the bimetallic strip 38 the arm 24 is permitted to move downwards so that contacts 26-21 are separated. Furthermore, by disconnecting the generator from the conductor 45 before the battery is disconnected therefrom, the possibility of the devices in circuit `with said conductor being damaged by an excessive circuit from the generator, is obviated.

In the further modification shown in Figure 10. the contact arm I9 is electrically connected to the battery I'I as in Figure 1 while the conarm 24 is provided with a conductor 45 which leads to the ignition andother switches shown in Figure 1.A

An electromagnet 68 arranged vertically within the casing I8 coactswith an armature on the free end of the contact arm I9 and this magnet S8 is provided with twojwindings shown diagrammatically at 69 and 10. is arranged in parallel with the-starting motor I8 and is therefore energised when the starter switch IB is closed while the winding 10 is connected by a conductor 1I to a conductor 12 which connects the generator 13 to the automatic cut out switch 58.

A bimetallic strip 14 arranged above the contact. arm has its upper end secured to the casing I8 whilst a cap on its lower end normally engages a shoulder formed by one end of a contact member 15 secured to the said contact arm the arrangement being generally similar to that of the bimetallic strip38 in Figure 1.

When the starting switch I6 is depressed the winding 69 of the electromagnet 68 is energised to attract the armature on the contact arm I9 which thereby descends so that the contacts 26 and 21 are vclosed as in theprevious constructions.

The downward movement of the arm i9 allows the bimetallic strip 14 to assume its vertical position with the result that contacts 26 and 21 cannot be separated until a predetermined time delay takes place.

When the engine starts the winding 'I8 of the electromagnet 68 is energisedby current from the generator 13 and it is to be noted that this energisation is effectedbefore the usual automatic cut out switch 58 is closed. Consequently the arm I9 which was pulled downwards as a result of the energisationof the winding 69 is held down during the normal operation of the engine, as a result of the energisation of the winding 10.V f v rf the lengineshould be stalledv or the ignitionl circuit `opened the winding 10 is de-energised and the Contact' arm I9 vis released whereby it undergoes a small upward movement'which is arrested by the contact memberf15'thereon moving into engagement with the conductor cap on the lower end of the bimetallic strip 14. This upward movementv is insufficient to permit contacts 26 and 21 to separate.

. The winding of the bimetallic strip is therefore energised in the manner previously described so that after the lapse of a predetermined period the lower end of the bimetallic strip moves lat- The winding 69 erally over the end of the contact member 15 and allows `a. further upward movement of the arm I8 to take place so that the contacts 28 and 21 are separated.

Yet vanother modification is shown in Figure 11 in which the upper contact arm I9 is extended and is provided at its free end with an armature which is arranged to coact with an electromagnet 18 the core 'I9 of which is formed of one of several known alloys the magnetic permeability of which decreases rapidly when the alloys are raised to particular temperatures. The winding of the magnet is connected inparallel with the starting motor whereby it isjenergised to attract its armature when the starter switch is closed. The armature and the core of the magnet constitute self holding contactsfor which purpose a conductor 83 passes from the core to the adjacent end of the winding, portion of which is formed of resistance wire.

The downward displacement ofthe arm I consequent upon the energisation of the magnet 18 causes a. contact on the underside thereof to engage a contact on the upper surface of a resilient arm 80 which is formed integrally with a similar arm 8| arranged horizontally therebelow, these arms being connected to a terminal 82.

The arm 8! is provided on its underside with a contact which normally is disposed clear of a contacton the upper face of the4 contact arm 24; The bimetallic strip 38 operates in themanner described with reference to Figure 1 of the drawing.

A vertical plunger 42 is arranged below the contact arm 24 and its lowerend is pivoted to a lever 84 the opposite end of which is connected to a rod 85 having its lower end secured to a flexible diaphragm accommodated within a diaphragm' chamber 86. A` pipe 81 connected to the lower end of the diaphragm chamber is led to the induction manifold of the engine, in which a. partial vacuum is maintained when the engine is running.

The terminals 2l and 25 are both connected to theconductor 44 which as shown in ,Figure 1 leads to the ignition and other switches of the vehicle while the terminal 82 is connected to the battery.

When the starting switch I6 is closed the winding of the electromagnet 18 is energised whereby the contact arm I9 is moved downwardly rent then flows from the battery through arm 8ll, arm I9 and armature thereon to the core 19 of the magnet, conductor 83 andthe winding of the magnet to earth. The magnet 18 therefore remains energised when the starting switch is opened. However the resistance wire included in the lwinding of the magnet causes the temperature-of the core 19 to increase and when the critical temperature is reached the released, thereby breaking-the self holding circuit and separating the contacts on the contact arms I9 and 8U.

When, however, the engine starts, consequent upon the operation of the starting switch, the partial vacuum lcreated in the induction manifold causes the diaphragm within the chamber 486 to be displaced downwards so that the plunger 42 is moved upwards to impart movement to the contact arm 24 and cause the contact 'on its upper face to engage the contact on the arm 8|. The engagement of these contacts is effected before the corresponding contacts on into engagement with the contact arm 88. -Curvmagnetic *fluxy falls sharply and the armature is the arms I9 and 80 are separated so that the opening of the latter do'es not ordinarily effect the equipment in circuit with conductor 45.

When the engine stops the plunger 42 descends to permit the contact arm 24 to move downwards into engagement with the cap on the blmetalllc strip 30 and after a predetermined lapse of time the said cap moves laterally through a sumcient distance to permit the arm 2H to undergo a further downward movement whereby the parts are restored to the positions shown in Figure il.

It is convenient to utilise the usual starting switch as previously described to effect the temporary closure of the switching means included in the casing Hl, as by so doing no additional step is introduced into the operations which are necessarily involved in starting the engine. It will be evident however that if desired a separate push button or other suitable type o1' switch 1 may be provided for this purpose. Thus for example the switch I6 shown in Figure 1l. may be regarded as being an independent push button switch arranged in any position which is conveniently accessible to the driver.

I claim:

i. In an electric circuit of a motor vehicle, a source of electric energy, a device in circuit with said source of energy, auxiliary switching means operable to temporarily close a break in said circuit, manually operable means for effecting the actuation of said auxiliary switching means, time delay means operable to cause said break to remain closed for a minimum period consequent upon the actuation of said manually operable means and automatic switching means responsive to the running of theengine to maintain said break closed during normal operationv thereof.

2. In an electric circuit associated with an engine, an electric battery, adevice in circuit with said battery, means normally interrupting said vsaid manually operable means and means responsive to the running of the engine for maintaining said interrupting means closed during normal operation of the engine.

3. Apparatus comprising an internal combustion engine, electric ignition means for said engine, an electric battery arranged in circuit with the ignition means, switching means in said circuit, said switching means being normally open when the engine is not running, manually operable means ior closing said switching means, time delay means operative to maintain said switching means closed for at least a minimum period following the operation of said manually operable means, means responsive to the running of the engine for maintaining said switching means closed during normal operation thereof and an ignition switch in series with said switching means.

4. An apparatus according to claim 3,an electric lamp in circuit with the said switching means and in parallel with said ignition means,-a bimetallic strip, means operable upon the closure of said switching means to permit displacement of said becoming inoperative, to close the circuit of said resistance winding. chaetracterized in that the consequent increase in temperature of the bimetallic strip causes same to be displaced to permit reopening of the said switching means.

5. Apparatus comprising an internal combustion engine having a pressure lubrication system, electric ignition means for said engine, an electric battery arranged in circuit with the ignition means, a pair of switches arranged in parallel in said circuit, both of said switches being normally open when the engine is not running, manually` operable means for effecting the closure of one of said switches, time delay means operative to cause said last mentioned switch to reopen after a limited period, means responsive to the pressure o f the lubricating oil to close the other said switch and an ignition switch in series with said pair ci switches.

o 6. Apparatus comprising an internal combus# tion engine having a pressure lubrication system, an electric battery, electric ignition means in cir= cuit with the battery, said circuit being normally interrupted between two points therein when the engine is not running, a starting motor and a starting switch in another circuit of said battery, means operable upon actuation of the starting switch to close the ignition circuit between said points therein, means responsive to the pressure of the lubricating oil to maintain the ignition circuit closed between said two points during normal operation of the engine, time delay means operable to interrupt the circuit between said two points therein unless said means responsive to the pressure responsive means has been actuated within a limited period following the operation of the starting switch and an ignition switch in circuit with the ignition means.

'1. Apparatus comprising an internal combustion engine, an electric battery, electric ignition means in circuit with the battery, said circuit being normally interrupted between two points therein when the engine is not running, an expansible resistance element in another circuit or" said battery, a manually controlled switch in the last mentioned circuit, means operable consequent upon the energization and expansion of said resistance element to close the ignition circuit between sad two points therein, said last mentioned means tending to interrupt the circuit consequent upon the de-energization and contraction of the resistance element, means responsive to normal operation of the engine to maintain the ignition circuit closed between said two points therein and an ignition switch in the said ignition circuit.

8. Apparatus comprising an internal combus tion engine having a pressure lubrication system, an electric battery, electric ignition means in circuit with the battery said circuit being normally interrupted between two points therein when the engine is not running, a resistance element in another circuit of the battery, a manually controlled switch in circuit with the resistance element, means operable consequent upon energization and expansion of the resistance element to temporarily close the ignition circuit between said two points therein, means responsive to the pressure of the lubricating oil, to maintain said ignition circuit closed between said points therein when said oil pressure exceeds a predetermined value and an ignition switch in said ignition circuit.

9. Apparatus comprising an internal combustion engine having a pressure lubricating system, an electric batte;y, ignition means, an electric lamp, said ignition means and said electric lamp being arranged in parallel circuits of said battery, a circuit element common to said parallel circuits, said common circuitI element being normally interrupted -between two points therein l when the engine -is not running, a starting motor,

a starting switch in circuit with said starting motor and said battery, means operable consequent upony actuation of the starting switch to close said common circuit element between said points therein means responsive to the pressure of the lubricating oil for maintaining the circuit closed between said points during normal operation of the engine, and time delay means operable consequent upony release of the starting switch to reopen the circuit between said two points if said means responsive to the oil pressure has not been actuated within a predetermined time.

1,0. Apparatus according to'claim 9 including time delay means operable consequent upon said means, responsive to operation of the engine, becoming inoperative tov delay reopening of the circuit between said two points therein.

l1'. Apparatus comprising an internal combustion engine, an electric battery,a device in circuit with said battery, said circuit being normally interrupted betweenv two points therein when the engine is not running, manually controlled means operable to eect the closure of the circuit between said points therein, means operable responsive to the operation of the engine to maintain the circuit closed between said points during normal operation of the engine, and time delay means Aengine having a pressure lubrication system, electric ignition means for said engine, an electric battery arranged in circuit with the ignition means, an electric lamp in a parallel circuit of said battery, switching means in circuit with said ignition means and vsaid electric lamp, said switching means being normally openwhen the Vengine is not running, manually operable means for effecting the closure of saidswitching means, time delay means operative to maintain said switching means closedior a minimum period following the operation of said manually operable y means, means responsive to the pressure of the Ato lubricating oil for .maintaining said switching means closed during normal operation of the engine, an ignition switch arranged in the said circuit in series with said switching means and time delay means operative to maintain said switching means closed fora limited period after said means, responsive to the running of the engine, becomes inoperative.i

13. In a motor vehicle, an internal combustion engine having a pressure lubrication system, electric ignition means for said engine, an electric battery arranged in circuit with the ignition means, a switch in said circuit, manually controlled means operable to close said switch, means responsive to the pressure of lubricating oil for maintaining said switch closed Vduring the normal operation of the engine, means operative within a limited time yafter said manually controlled means has been operated to reopen said-switch engine having a pressure lubrication system, electric ignition means for said engine, an electric battery in circuit with the ignition means, a movable switch member -in said circuit, a coacting switch member in said circuit, said movable switch member being biased for movement towards the coacting switch member, an expansible electric resistance element, means connecting the movable switch member tothe resistance element whereby said movable switch member is normally held out of contact with the coacting switch member, manually operable means for causing said electric resistance element to be energized from said battery whereby said resistance element will expand and permit the movable switch member to engage the coacting switch member, and means responsive to the pressure of the lubricating oil to maintain said switch members in engagement during normal operation of the engine.

15. -In a motor vehicle according to claim 14 a resilient bimetallic strip having one end fixed whereby its opposite end is displaceable from an inoperative to an operative position, means operable, consequent upon actuation of said means responsive to the pressure of the lubricating oil, to permit movement of the bimetallic strip to its operative position, said bimetallic strip when disposed in its operative position preventing separation of the switch members, a resistance winding for the bimetallic strip and means operative consequent upon said pressure responsive means, becoming inoperative, to energize said winding whereby the bimetallic strip is heated and is displaced into its original inoperative position.

16. In a motor vehicle, an internal combustion engine having a pressure lubrication system, electric ignition means for said engine, an electric battery in circuit with the ignition means, a resilient switch arm in said circuit, a second resilient `switch arm in said circuit and disposed adjacent to the iirst mentioned switch arm, said iirst mentioned switch arm being. biased for movement towards the second switch arm, an expansible electric resistance element, means supporting the ends of the resistance element, means connecting the first mentioned switch arm to an intermediate portion of the resistance element, whereby said rst mentioned switch arm is normally held out of contact with the second switch arm, manually operable means for causing said electric resistance element to be energized from said battery whereby said resistance element will expand and permit the iirst mentioned switch arm to move into engagement with the second switch arm, and means responsive to the pressure of the lubricating oil for imparting movement to the second switch arm in the direction of the rst mentioned switch arm.

17. In a motor vehicle, an internal combustion engine having a pressure lubrication system, electric ignition means .for said engine, an electric battery in circuit with the ignition means, a resilient switch arm in said circuit, a second resilient switch arm insaid circuit and disposed adjacent to the first mentioned switch arm, said iirst mentioned switch arm being biased for movement towards the second switch arm, an expansible electric resistance element, means supporting the ends of the resistance element, means connecting the first mentioned switch arm to an intermediate portion of the 'resistance e1ement,where by said first mentioned switch arm is normally held out of contact with the said second switch arm, manually operable means for causing said electric resistance element to be energized from said battery whereby said resistance element will expand and permit the first mentioned switch arm to move into engagement with the second switch arm, means responsive to the pressure of the lubricating oil for imparting a closing movement to the second switch arm in the direction of the first mentioned switch arm, a bimetallic strip fixed at one end and having its opposite end arranged to coact with the second mentioned switch arm, means maintaining the free end of the bimetallic strip in an inoperative position until a closing movement is imparted to the second mentioned switch arm, said bimetallic strip, when in its operative position, serving to prevent disengagement of the said switch arms, a resistance Winding for the bimetallic strip, and means operable when said means responsive to oil pressure, becomes inoperative, to energize said winding whereby the bimetallic strip is displaced to permit disengagement of the said switch arms.

18. In a motor vehicle, an internal combustion engine having a pressure lubrication system, electric ignitionvmeans for said engine, an electric battery in circuit with the ignition means, a resilient switch arm in said circuit, a contact in said circuit; said contact being disposed adjacent to but normally out of engagement with the switch arm, an electro-magnet energizable to move said switch arm into engagement with said contact, manually operable means for effecting energization of said electromagnet, time delay means operable to maintain engagement between said switch arm and said contact for a predetermined period, and means responsive to the pressure of the lubricating oil for maintaining said switch arm in engagement with the contact during normal operation of the engine.

ERNEST GEORGE LACEY. 

